1. Field of the Invention
The present invention relates generally to improved methods and apparatus for manufacturing scored reverse buckling rupture disks, and more particularly, but not by way of limitation, to methods and apparatus for manufacturing scored reverse buckling rupture disks having concave-convex dome portions and scores radiating outwardly from central portions thereof.
2. Description of the Prior Art
Many safety pressure relief devices of the rupture disk type have been developed and used heretofore. Generally, such devices include a rupture disk supported between a pair of supporting members or flanges which are in turn connected to a relief connection in a vessel or system containing fluid pressure. When the pressure within the vessel or system exceeds the design rupture pressure of the disk, rupture occurs causing excess fluid pressure to be relieved from the vessel or system.
Rupture disks of the reverse buckling type, i.e., the fluid pressure is exerted on the convex side of the dome portion of the disk and upon failure the dome portion reverses and then ruptures, have also been developed and used successfully. Originally, such reverse buckling rupture disk assemblies included a reverse buckling rupture disk supported between inlet and outlet supporting members with a set of knife blades positioned adjacent the disk on the outlet side thereof so that when excessive fluid pressure was exerted on the convex side of the disk, the concave-convex portion reversed itself and impaled on the knife blades causing the concave-convex portion to open in a predetermined manner.
More recently, reverse buckling rupture disks have been developed which include scores or grooves on a surface of the concave-convex portion thereof creating lines of weakness therein so that upon reversal of the disk the concave-convex portion tears along the lines of weakness and opens without fragmentation. A method of manufacturing such disks is described and claimed in U.S. Pat. No. 3,921,556 issued Nov. 25, 1975 and assigned to the assignee of this present invention. While the method described in U.S. Pat. No. 3,921,556 has been used successfully for manufacturing scored reverse buckling rupture disks, because the depth variance of the scores formed in accordance with the method cannot be changed in the manufacturing process, a number of reforming and annealing steps are required to achieve the manufacture of scored reverse buckling rupture disks having desired operational characteristics. The term "depth variance" is used herein to mean the variation in depth of each of the scores formed on a disk from the central portion of the concave-convex dome portion of the disk towards the periphery thereof.
By the present invention, improved methods and apparatus for manufacturing scored reverse buckling rupture disks are provided which, because the depth variance of the scores can be adjusted during the manufacturing process, eliminates all or part of the reforming and annealing steps previously required. In addition, the scored reverse buckling rupture disks manufactured in accordance with the method of the present invention have improved operational characteristics.